Bipolar membranes (BPMs) are emerging options for kinetically accelerating water dissociation (WD) in electrochemical applications. Graphene oxide (GO) with abundant oxygenated functional groups is an efficient catalyst within BPMs to decrease the transmembrane potential. However, the dominant catalytic sites on GO for WD in BPMs have not been experimentally identified, and the reported simulative calculation results are controversial. Herein, we prepared carboxylated and partially hydroxylated GO-based BPMs, and for the first time quantitatively unraveled the correlativity between WD performance and carboxyl group content with tailor-designed experiments. By using a simple mechanical ball milling method, we further improved the bulk density of carboxyl on the GO catalyst, which achieved excellent WD performance during an operation of over 130 h operation. This study provides a subtle and facile strategy for catalyst design to advance BPM technologies.

中文翻译：

---

鉴定氧化石墨烯上的关键含氧官能团，以实现双极膜中高效水解离


双极膜 （BPM） 是电化学应用中动力学加速水解离 （WD） 的新兴选择。具有丰富含氧官能团的氧化石墨烯 （GO） 是 BPM 中降低跨膜电位的有效催化剂。然而，尚未通过实验确定 BPMs 中 WD 在 GO 上的主要催化位点，并且报道的模拟计算结果存在争议。在此，我们制备了羧化和部分羟基化的基于 GO 的 BPMs，并通过定制设计的实验首次定量揭示了 WD 性能和羧基含量之间的相关性。通过使用简单的机械球磨方法，我们进一步提高了 GO 催化剂上羧基的堆积密度，在超过 130 小时的运行中实现了出色的 WD 性能。本研究为催化剂设计提供了一种微妙而简单的策略，以推进 BPM 技术。